Vertical light emitting diode with magnetic back contact

ABSTRACT

A structure containing a vertical light emitting diode (LED) is provided. The vertical LED is present in an opening located in a display substrate, and the vertical LED is coupled to a back contact structure via a magnetic back contact structure. A first top contact structure contacts a topmost surface of the vertical LED and a second top contact structure contacts a surface of the back contact structure.

BACKGROUND

The present application relates to a structure containing a verticallight emitting diode (LED) and a method of forming the same.

A light emitting diode (LED) is a two-lead semiconductor light source.An LED is a p-n junction diode, which emits light when activated. When asuitable voltage is applied to the leads, electrons are able torecombine with electron holes within the device, releasing energy in theform of photons. This effect is called electroluminescene, and the colorof the light (corresponding to the energy of the photon) is determinedby the energy band gap of the semiconductor material used to provide thep-n junction.

Prior art devices contain lateral LEDs in which contact is made to thesidewalls of the LEDs. Lateral LEDs typically contain high resistanceand thus low performance. There is thus a need for providing a structurecontaining a LED in which the resistance is reduced and the performanceis enhanced as compared to the lateral LED containing structures of theprior art.

SUMMARY

A structure containing a vertical light emitting diode (LED) isprovided. The vertical LED is present in an opening located in a displaysubstrate, and the vertical LED is coupled to a back contact structurevia a magnetic back contact structure. A first top contact structurecontacts a topmost surface of the vertical LED and a second top contactstructure contacts a surface of the back contact structure.

In one aspect of the present application, a structure is provided thatcontains a vertical light emitting diode (LED). In one embodiment, thestructure includes an opening located in a display substrate. A first(i.e., bottom) contact structure lines at least one sidewall of theopening and a bottom wall of the opening. A first magnetic material islocated on a portion of the first contact structure that is located onthe bottom wall of the opening, a second magnetic material is located ona surface of the first magnetic material, and a vertical light emittingdiode is located on a surface of the second magnetic material. Thestructure also includes a pair of second (i.e., top) contact structures,wherein one of the second contact structures is in direct contact with atopmost surface of the vertical light emitting diode, and another of thesecond contact structures is in direct contact with a surface of thefirst contact structure.

In another aspect of the present, a method of forming a structurecontaining a vertical light emitting diode (LED) is provided. In oneembodiment, the method may include providing an opening in a displaysubstrate. Next, a first contact structure is formed on at least onesidewall of the opening and a portion of a bottom wall of the opening. Afirst magnetic material is then formed on a portion of the first contactstructure that is located on the bottom wall of the opening. Next, afirst surface of a second magnetic material of a material stack isbonded to the first magnetic material, wherein the material stackincludes a vertical light emitting diode located on a second surface ofthe second magnetic material, the second surface is opposite the firstsurface. A pair of second contact structures is then formed, wherein oneof the second contact structures is in direct contact with a topmostsurface of the vertical light emitting diode, and another of the secondcontact structures is in direct contact with a surface of the firstcontact structure.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a cross sectional view of a first exemplary structureincluding an opening located in a display substrate that can be employedin accordance with an embodiment of the present application.

FIG. 2 is a cross sectional view of the first exemplary structure ofFIG. 1 after forming a first (i.e., bottom) contact structure lining atleast one sidewall of the opening and located on the bottom wall of theopening.

FIG. 3 is a cross sectional view of the first exemplary structure ofFIG. 2 after forming a first magnetic material on a portion of the firstcontact structure that is located on the bottom wall of the opening.

FIG. 4 is a cross sectional view of a second exemplary structureincluding a material stack of a second magnetic material and a verticalLED that can be employed in accordance with an embodiment of the presentapplication.

FIG. 5 is a cross sectional view of the exemplary structures of FIGS.3-4 after bonding the second magnetic material to the first magneticmaterial.

FIG. 6 is a cross sectional view of the exemplary structure of FIG. 5after forming a dielectric material.

FIG. 7 is a cross sectional view of the exemplary structure of FIG. 6after forming second (i.e., top) contact structures, wherein one of thesecond contact structures is in direct contact with a portion of thetopmost surface of the vertical LED, and wherein another of the secondcontact structures is in direct contact with a surface of the firstcontact structure.

DETAILED DESCRIPTION

The present application will now be described in greater detail byreferring to the following discussion and drawings that accompany thepresent application. It is noted that the drawings of the presentapplication are provided for illustrative purposes only and, as such,the drawings are not drawn to scale. It is also noted that like andcorresponding elements are referred to by like reference numerals.

In the following description, numerous specific details are set forth,such as particular structures, components, materials, dimensions,processing steps and techniques, in order to provide an understanding ofthe various embodiments of the present application. However, it will beappreciated by one of ordinary skill in the art that the variousembodiments of the present application may be practiced without thesespecific details. In other instances, well-known structures orprocessing steps have not been described in detail in order to avoidobscuring the present application.

It will be understood that when an element as a layer, region orsubstrate is referred to as being “on” or “over” another element, it canbe directly on the other element or intervening elements may also bepresent. In contrast, when an element is referred to as being “directlyon” or “directly over” another element, there are no interveningelements present. It will also be understood that when an element isreferred to as being “beneath” or “under” another element, it can bedirectly beneath or under the other element, or intervening elements maybe present. In contrast, when an element is referred to as being“directly beneath” or “directly under” another element, there are nointervening elements present.

Referring first to FIG. 1, there is illustrated a first exemplarystructure including an opening 12 located in a display substrate 10 thatcan be employed in accordance with an embodiment of the presentapplication. Although the present application describes and illustratesa single opening 12, a plurality of spaced apart openings can be formedinto the display substrate 10 and can be used in the presentapplication.

The display substrate 10 that can be employed in the present applicationmay include various materials such as, for example, a semiconductormaterial, an insulator or any combination thereof. The term“semiconductor material” is used throughout the present application todenote a material that exhibits semiconducting properties. Examples ofsemiconductor materials that can be used to provide the displaysubstrate 10 include, for example, silicon (Si), germanium (Ge), silicongermanium alloys (SiGe), silicon germanium carbide (SiGeC), III-Vcompound semiconductors or II-VI compound semiconductors. III-V compoundsemiconductors are materials that include at least one element fromGroup III of the Periodic Table of Elements and at least one elementfrom Group V of the Periodic Table of Elements. II-VI compoundsemiconductors are materials that include at least one element fromGroup II of the Periodic Table of Elements and at least one element fromGroup VI of the Periodic Table of Elements. In one embodiment of thepresent application, silicon is employed as the material that providesthe display substrate 10.

The semiconductor material that provides the display substrate 10 may bea single material or a combination of semiconductor materials. In someembodiments, a semiconductor-on-insulator including a handle substrate,a buried oxide, and a top semiconductor material may be used as thedisplay substrate 10.

The insulator material that may be employed as the display substrate 10includes any electrical insulating material such as, for example, glass,a ceramic (such as a carbide, an oxide or a nitride), and/or a plastic.The insulator material that provides the display substrate 10 may becomposed of a single electrical insulating material or a combination ofelectrical insulating materials. In some embodiments, a material stack,in any order, of a semiconductor material and an insulator material maybe employed as the display substrate 10.

The display substrate 10 may have a thickness from few microns (e.g., 2microns) to a few millimeters (e.g., 3 millimeters). Other thicknessesthat are lesser than, or greater than, the aforementioned thicknessvalues may be employed as the thickness of the display substrate 10.

The opening 12 that is formed into the display substrate 10 includessidewalls (S1 and S2) and a bottom wall (BW). In some embodiments, andas shown, the sidewalls S1 and S2 are vertical with respect to thebottom wall (BW) of the opening 12. In other embodiments, the sidewallsS1 and S2 are tapered with respect to the bottom wall (BW) of theopening 12. The opening 12 can be formed by patterning the material ormaterial stack that provides the display substrate 10. In oneembodiment, patterning may be performed by lithography and etching.Lithography includes forming a photoresist (not shown) atop a materialor material stack to be patterned, exposing the photoresist to a desiredpattern of radiation, and developing the exposed photoresist utilizing aconventional resist developer. The photoresist may be a positive-tonephotoresist, a negative-tone photoresist or a hybrid-tone photoresist.The etching process includes a dry etching process (such as, forexample, reactive ion etching, ion beam etching, plasma etching or laserablation), and/or a wet chemical etching process. Typically, reactiveion etching is used in providing the opening 12. The opening 12 stopswithin the display substrate 10 exposing a sub-surface portion of thedisplay substrate 10. By “sub-surface portion” it is meant a portion ofa material that is located between a topmost surface and a bottommostsurface of the material. When multiple openings are formed, the openingsmay have a same depth, or they may have different depths.

Referring now to FIG. 2, there is illustrated the first exemplarystructure of FIG. 1 after forming a first contact structure 14 lining atleast one sidewall (i.e., S1) of the opening 12 and located on thebottom wall (BW) of the opening 12. In one embodiment, and as shown, aportion of the first contact structure 14 is located on a topmostsurface of the display substrate 10. In the illustrated embodiment, thefirst contact structure 14 lines only one sidewall (i.e., S1) of theopening 12 and is present only on a portion of the bottom wall (BW) ofthe opening 12. In other embodiments (not shown), the first contactstructure 14 may line each sidewall (S1, and S2) and be present on theentirety of the bottom wall (BW) of the opening 12. In such anembodiment, portions of the first contact structure 14 may extend ontothe topmost surface of the display substrate 10 on both sides of theopening 12.

The first contact structure 14 is composed of any ohmic metal or metalalloy. Examples of ohmic metals or metal alloys that may be employed inproviding the first contact structure 14 include, but are not limitedto, nickel, cobalt, aluminum, titanium, tungsten, palladium, platinum,or nickel silver. The first contact structure 14 may be formed by firstproviding a blanket layer of an ohmic metal or metal alloy. The blanketlayer of ohmic metal or metal alloy can be formed utilizing a depositionprocess such as, for example, chemical vapor deposition, plasma enhancedchemical vapor deposition, physical vapor deposition, atomic layerdeposition, sputtering or plating. After providing the blanket layer ofohmic metal or metal alloy, the blanket layer of ohmic material may bepatterned. In one embodiment, patterning may be performed by lithographyand etching as defined above.

The first contact structure 14 may have a thickness from 20 nm to 500nm. Other thicknesses that are lesser than, or greater than, theaforementioned thickness values may also be used as the thickness of thefirst contact structure 14. In some embodiments, the first contactstructure 14 has a conformal thickness. In such an embodiment, thethickness of the first contact structure 14 as measured upwards from ahorizontal surface of the display substrate 10 is the same as thethickness of the first contact structure as measured outward from avertical surface of the display substrate 10.

Referring now to FIG. 3, there is illustrated the first exemplarystructure of FIG. 2 after forming a first (i.e., bottom) magneticmaterial 16 on a portion of the first contact structure 14 that islocated on the bottom wall (BW) of the opening 12. As is shown, thefirst magnetic material 16 is present entirely in the opening 12 and isin direct contact with a portion of the first contact structure 14. Thefirst magnetic material 16 does not cover the entirety of the firstcontact structure 14 that is located on the bottom wall (BW) of theopening 12. As such, a gap is present between a sidewall of the firstmagnetic material 16 and the first contact structure 14 that lines thesidewall(s) of the opening 12.

The first magnetic material 16 may be composed of any material that hasmagnetic properties. In one embodiment of the present application, thefirst magnetic material 16 is composed of a magnetic metal or metalalloy such as, for example, magnetic nickel, magnetic cobalt, magneticiron or magnetic alloys thereof. In one embodiment, the first magneticmaterial 16 is composed of magnetic nickel. The first magnetic material16 may be formed by first providing a blanket layer of magneticmaterial. The blanket layer of magnetic material can be formed utilizinga deposition process such as, for example, chemical vapor deposition,plasma enhanced chemical vapor deposition, physical vapor deposition,atomic layer deposition, sputtering or plating. After providing theblanket layer of magnetic material, the blanket layer of magneticmaterial may be patterned. In one embodiment, patterning may beperformed by lithography and etching as defined above.

The first magnetic material 16 may have a thickness from 100 nm to 10000nm. Other thicknesses that are lesser than, or greater than, theaforementioned thickness values may also be used as the thickness of thefirst magnetic material 16.

Referring now to FIG. 4, there is illustrated a second exemplarystructure that includes a material stack 18 of a second magneticmaterial 20 and a vertical LED 22 that can be employed in accordancewith an embodiment of the present application. The material stack 18 isdesigned to have sidewall surfaces that are vertically aligned with thesidewall surfaces of the first magnetic material 16.

The second magnetic material 20 that can be employed in the presentapplication includes any material that exhibits magnetic properties andcan be attracted to the first magnetic material 16 by magnetic force ofattraction. In one embodiment, the second magnetic material 20 may becomposed of a same magnetic material as the first magnetic material 16provided that magnetic force of attraction exists between the twomagnetic materials. In such an embodiment, magnetic nickel can be usedas the magnetic material for both the first and second magneticmaterials (16, 20). In another embodiment, the second magnetic material20 may be composed of a different magnetic material than the firstmagnetic material 16 provided that magnetic force of attraction existsbetween the two magnetic materials. The second magnetic material 20 maybe formed utilizing one of the deposition techniques mentioned above forproviding the first magnetic material 16.

The second magnetic material 20 may have a thickness from 100 nm to10,000 nm. Other thicknesses that are lesser than, or greater than, theaforementioned thickness values may also be used as the thickness of thesecond magnetic material 20.

The formation of the second magnetic material 20 can occur prior to, orafter forming, the vertical LED 22. In some embodiments, the materialstack 18 is formed by first providing blanket layers of the variousmaterials and then subjecting the blanket layers of the variousmaterials to a patterning process such as, for example, lithography andetching as defined above.

The vertical LED 22 includes a stack of, from bottom to top, a firstsemiconductor material 24 of a first conductivity type, and a secondsemiconductor material 26 of a second conductivity type that differsfrom the first conductivity type. In one embodiment, the firstconductivity type is p-type and the second conductivity type is n-type.In another embodiment, the first conductivity type is n-type and thesecond conductivity type is p-type. The term “p-type” refers to theaddition of impurities to an intrinsic semiconductor that createsdeficiencies of valence electrons. “N-type” refers to the addition ofimpurities that contributes free electrons to an intrinsicsemiconductor. The concentration of dopants that provide the first andsecond conductivity types may be from 1×10¹⁸ atoms/cm³ to 5×10²¹atoms/cm³; other dopant concentrations as possible so long as a p-njunction is provided between the first and second semiconductormaterials (24, 26).

The first and second semiconductor materials (24, 26) of material stack18 include any semiconductor material or combination of semiconductormaterials that when a suitable voltage is applied thereto, electrons areable to recombine with electron holes, releasing energy in the form ofphotons. In one embodiment of the present application, the first andsecond semiconductors materials (24, 26) are both composed of a III-Vcompound such as for example, GaN or GaAs.

The LED structure 22 including the first and second semiconductormaterials (24, 26) may be formed utilizing any well known method. In oneembodiment, an intrinsic base semiconductor material is provided by anepitaxial growth process. The intrinsic base semiconductor material maythen be doped to provide the first and second semiconductor materials(24, 26). In another embodiment, the first semiconductor material 24 ofthe first conductivity type can be formed first, and thereafter thesecond semiconductor material 26 of the second conductivity type can beformed on the first semiconductor material 24 utilizing an epitaxialgrowth process. The dopant that provides the second conductivity typecan be introducing during the epitaxial growth process itself, or afterepitaxial growth utilizing any well known method such as, for example,gas phase doping or ion implantation. In yet other embodiments, thesecond semiconductor material 26 may be form first, followed byepitaxial growth of the first semiconductor material 24. In such anembodiment, the dopant that provides the first conductivity type can beintroducing during the epitaxial growth process itself, or afterepitaxial growth utilizing any well known method such as, for example,gas phase doping or ion implantation.

In another embodiment, the LED structure 22 may be formed utilizing aspalling (i.e., a material removal process). Spalling is a usefultechnique in creating thin film devices by fracturing a surface of acrystalline substrate through use of stress created by differences inmaterial properties of the material to be fractured and a stressormaterial. In embodiments in which spalling is employed, the first andsecond semiconductor materials (24, 26) of the LED structure 22 areformed on base substrate. Next, a stressor layer such as a layer ofnickel is formed on top of the first and second semiconductor materials(24, 26), wherein the metal stressor layer is deposited to a thicknesssufficient to permit mechanically-assisted spalling of the first andsecond semiconductor materials (24, 26) to occur. A handle layer such asan adhesive tape is then formed on stressor layer and thereafter thefirst and second semiconductor materials (24, 26) are removed from thebase substrate by pulling the handle layer away from the base substrate.

The first and second semiconductor materials (24, 26) of material stack18 may each have a thickness from 50 nm to 2000 nm. Other thicknessesthat are lesser than, or greater than, the aforementioned thicknessvalues may also be used as the thickness of the first and secondsemiconductor materials (24, 26).

The thickness of the material stack 18 is typically, but not necessarilyalways, designed such that the entirety of the material stack 18 can besubsequently confined within the opening 12 provided in the displaysubstrate 10. In one embodiment, the thickness of the material stack 18can be from 100 nm to 10,000 nm.

Referring now to FIG. 5, there is illustrated the exemplary structuresof FIGS. 3-4 after bonding the second magnetic material 20 of thematerial stack 18 to the first magnetic material 20. The first andsecond magnetic materials (16, 20) are employed as a magnetic backcontact, and collectively the first and second magnetic materials (16,20) may be referred to as a magnetic back contact structure.

In the present application, bonding can be achieved by bringing aphysically exposed surface of the second magnetic material 20 of thematerial stack 18 in proximity to the first magnetic material 16 of thefirst exemplary structure and thereafter the two magnetic materials areattracted to each by magnetic force of attraction.

In some embodiments, an anneal may be performed to provide a permanentbond between the first and second magnetic materials (16, 20). In suchan embodiment, a solder material (not shown) such as, for example,indium, bismuth, gold, tin or alloys thereof can be formed utilizingconventional techniques that are well known to those skilled in the arton a surface of one or both of the first and second magnetic materials(16, 20) prior to bonding; during the anneal the solder material forms asoldered joint, i.e., permanent bond between the first and secondmagnetic materials (16, 20). The anneal (i.e., bonding anneal) may beperformed at a temperature from 100° C. to 1000° C., depending on theannealing time. Typically higher temperature requires less annealingtime. Annealing can be done by rapid thermal anneal (RTP), laser anneal,flash anneal, furnace anneal, or any suitable combination of thosetechniques. In one embodiment, the anneal is performed at 400° C. for 30seconds. Other temperatures may also be used as long as the annealtemperature is capable of forming a permanent bond between the magneticheld first and second magnetic materials (16, 20). In some embodiments,the anneal may be performed in an inert ambient such as, for example,helium and/or argon. In other embodiments, the anneal may be performedin a forming gas ambient. The duration of the anneal may vary so long asthe duration of the anneal causes the formation of a permanent bondbetween the magnetically held first and second magnetic materials (16,20).

As is shown in FIG. 5, each of the first magnetic material 16, thesecond magnetic material 20 and the vertical LED 22 (including the firstand second semiconductor materials (24, 26)) is entirely contained inthe opening 12. As is further shown, sidewalls of each of the firstmagnetic material 16, the second magnetic material 20 and the verticalLED 22 (including the first and second semiconductor materials (24, 26))are vertically aligned to each other. As is even further shown a gap islocated between the sidewalls of each of the first magnetic material 16,the second magnetic material 20 and the vertical LED 22 (including thefirst and second semiconductor materials (24, 26)) and the first metalcontact 14 that is present on the at least one sidewall (i.e., S1) ofthe opening 12.

Referring now to FIG. 6, there is illustrated the exemplary structure ofFIG. 5 after forming a dielectric material 28. The dielectric material28 is formed laterally adjacent and above the first contact structure14, the first magnetic material 16, the second magnetic material 20 andthe vertical LED 22. The dielectric material 28 extends above thetopmost surface of the display substrate 10 and covers a portion of thefirst contact structure that is present outside the opening 12. Thedielectric material 28 entirely embeds the first contact structure 14,the first magnetic material 16, the second magnetic material 20 and thevertical LED 22.

The dielectric material 28 may be composed of silicon dioxide, undopedsilicate glass (USG), fluorosilicate glass (FSG), borophosphosilicateglass (BPSG), a spin-on low-k dielectric layer, a chemical vapordeposition (CVD) low-k dielectric layer or any combination thereof. Theterm “low-k” as used throughout the present application denotes adielectric material that has a dielectric constant of less than silicondioxide. In another embodiment, a self-planarizing material such as aspin-on glass (SOG) or a spin-on low-k dielectric material such as SiLK™can be used as dielectric material 28. The use of a self-planarizingdielectric material as the dielectric material 28 may avoid the need toperform a subsequent planarizing step.

In one embodiment, the dielectric material 28 can be formed utilizing adeposition process including, for example, chemical vapor deposition(CVD), plasma enhanced chemical vapor deposition (PECVD), evaporation orspin-on coating. In some embodiments, particularly whennon-self-planarizing dielectric materials are used as the dielectricmaterial 28, a planarization process or an etch back process follows thedeposition of the dielectric material that provides the dielectricmaterial 28.

Referring now to FIG. 7, there is illustrated the exemplary structure ofFIG. 6 after forming second (i.e., top) contact structures (30A, 30B),wherein one of the second contact structures 30A is in direct contactwith a portion of the topmost surface (i.e., the second semiconductormaterial 26) of the vertical LED 22, and wherein another of the secondcontact structures 30B is in direct contact with a surface of the firstcontact structure 14. As is shown, a portion of the pair of secondcontact structures (30A, 30B) is embedded in the dielectric material 28.

The second (i.e., top) contact structures can be formed by firstproviding first and second contact openings (not shown) in thedielectric material 28. The first contact opening extends through thedielectric material 28 and physically exposes a portion of the topmostsurface (i.e., the second semiconductor material 26) of the vertical LED22, while the second contact opening extends through the dielectricmaterial 28 and physically exposes a surface of the first contactstructure 14 that is present outside the opening 12 and on the topmostsurface of the display substrate 10. Next, an ohmic metal or metal alloyis formed in each of the first and second contact openings; the ohmicmetal or metal alloy provides the second contact structures (30A, 30B)of the present application. The ohmic metal or metal alloy that providesthe second contact structures (30A, 30B) may include one of the ohmicmetals or metal alloy mentioned above in providing the first contactstructure 14. In one embodiment, the second contact structures (30A,30B) may include a same ohmic metal or metal alloy as the first contactstructure 14. In another embodiment, the second contact structures (30A,30B) may include a different ohmic metal or metal alloy as the firstcontact structure 14. The ohmic metal or metal alloy that provides thesecond contact structures (30A, 30B) may be formed utilizing adeposition process such as, for example, one of the deposition processesmentioned above for forming the ohmic metal or metal alloy of the firstcontact structure 14. Following the deposition of the ohmic metal ormetal alloy that provides the second contact structures (30A, 30B), apatterning process such as, for example, lithography and etching can beperformed to provide the exemplary structure shown in FIG. 7.

FIG. 7 illustrates a structure in accordance with the presentapplication. The structure illustrated in FIG. 7 includes an opening 12located in a display substrate 10. A first (i.e., bottom) contactstructure 14 lines at least one sidewall (S1) of the opening 12 and abottom wall (BW) of the opening 12. A first magnetic material 16 islocated on a portion of the first contact structure 14 that is locatedon the bottom wall (BW) of the opening 12, a second magnetic material 20is located on a surface of the first magnetic material 16, and avertical light emitting diode 22 (including the first and secondsemiconductor materials 24, 26)) is located on a surface of the secondmagnetic material 20. The structure also includes a pair of second(i.e., top) contact structures (30A, 30B), wherein one of the secondcontact structures (30A) is in direct contact with a topmost surface ofthe vertical light emitting diode 22, and another of the second contactstructures (30B) is in direct contact with a surface of the firstcontact structure 14. As is shown, the first and second contactstructures (14, 30A, 30B) do not contact any sidewall of the verticallight emitting diode 22. Instead, contact is made from the bottom of thelight emitting diode 22 (by the first contact structure 14 throughmagnetic bottom contact structure (16, 20)) and the top of the lightemitting diode 22 (through second contact structure 30A). The structureshown in FIG. 7 has reduced resistance and enhanced performance comparedto the lateral LED containing structures of the prior art.

While the present application has been particularly shown and describedwith respect to preferred embodiments thereof, it will be understood bythose skilled in the art that the foregoing and other changes in formsand details may be made without departing from the spirit and scope ofthe present application. It is therefore intended that the presentapplication not be limited to the exact forms and details described andillustrated, but fall within the scope of the appended claims.

What is claimed is:
 1. A method of forming a structure, the methodcomprising: providing an opening in a display substrate; forming a firstcontact structure on at least one sidewall of the opening and a bottomwall of the opening; forming a first magnetic material on a portion ofthe first contact structure that is located on the bottom wall of theopening; bonding a first surface of a second magnetic material of amaterial stack to the first magnetic material, wherein the materialstack includes a vertical light emitting diode located on a secondsurface of the second magnetic material, and wherein the second surfaceis opposite the first surface; and forming a pair of second contactstructures, wherein one of the second contact structures is in directcontact with a topmost surface of the vertical light emitting diode, andanother of the second contact structures is in direct contact with asurface of the first contact structure.
 2. The method of claim 1,further comprising forming a dielectric material located laterallyadjacent and above the first contact structure, the first magneticmaterial, the second magnetic material and the vertical light emittingdiode that are present in the opening, wherein the forming thedielectric material is performed prior to forming the pair of secondcontact structures.
 3. The method of claim 1, wherein the bondingincludes magnetic force of attraction of the first and second magneticmaterials.
 4. The method of claim 3, wherein the bonding furtherincludes performing an anneal to provide a permanent bond between thefirst and second magnetic materials.
 5. The method of claim 1, whereineach of the first magnetic material and the second magnetic material iscomposed of magnetic nickel.
 6. The method of claim 1, wherein thevertical light emitting diode includes a stack of, from bottom to top, afirst semiconductor material of a first conductivity type, and a secondsemiconductor material of a second conductivity type that differs fromthe first conductivity type.
 7. The method of claim 6, wherein each ofthe first semiconductor material and the second semiconductor materialis composed of an III-V compound semiconductor.
 8. The method of claim7, wherein the III-V compound semiconductor is composed of GaN or GaAs.9. The method of claim 1, wherein, after the bonding, sidewalls of eachof the first magnetic material, the second magnetic material and thevertical light emitting diode are vertically aligned to each other. 10.The method of claim 1, wherein the first contact structure lines onlyone sidewall of the opening, is present only on a portion of bottom wallof the opening and has a portion that extends onto a topmost surface ofthe display substrate.
 11. The method of claim 1, wherein the verticallight emitting diode is formed by a spalling process.
 12. The method ofclaim 1, wherein the first contact structure is present on both of thesidewall surfaces of the opening.
 13. The method of claim 1, wherein thefirst contact structure is of unitary construction and is composed of anohmic metal or metal alloy.
 14. The method of claim 1, wherein thesecond contact structures that is in direct contact with the topmostsurface of the vertical light emitting diode extends beneath a topmostsurface of the display substrate.
 15. The method of claim 1, whereineach of the first magnetic material, the second magnetic material andthe vertical light emitting diode is entirely contained in the opening.